Vacuum deposition apparatus

ABSTRACT

Vapor deposition apparatus includes a workholder formed as a shallow receptacle adapted to hold a disc type substrate. Receptacle sealing means is provided by a pivotally mounted cover member.

United States Patent Gorinas et al.

VACUUM DEPOSITION APPARATUS inventors: Guy Gorinas, St. Michel sur Orge;

Claude Ernu, Bobigny, both of France Assignee: Compagnie lndustrielle des Telecommunications Cit-Alcatel, Paris, France Filed: Dec. 21, 1972 Appl. No.: 317,307

Foreign Application Priority Data Dec. 21. 1971 France 7146010 US. Cl. 118/49, 118/50 Int. Cl. C23c 13/08 Field of Search 269/21;

118/4850.l; 214/1 BS, 1 ET, 1 BH, 1 EV; 294/64 R; 117/106-1072; 68/5 C; 128/1 NQ; 134/1 NQ [451 Oct. 9, 1973 [56] References Cited UNITED STATES PATENTS 2,746,420 5/1956 Steigerwald 118/491 X 3,309,221 3/1967 Smith 118/49.5 UX 3,694,894 10/1972 Velinek et al. 269/21 X Primary Examiner-Morris Kaplan Att0rneyPaul M. Craig, Jr. et al.

[ ABSTRACT Vapor deposition apparatus includes a workholder formed as a shallow receptacle adapted to hold a disc type substrate. Receptacle sealing means is provided by a pivotally mounted cover member.

9 Claims, 2 Drawing Figures PATENTEI] [ET 9 I975 SHEE 2 OF 2 VACUUM DEPOSITION APPARATUS The present invention concerns an enclosure for depositing thin layers in a vacuum, in which means are provided for protecting the substrates against any contaminations.

Known enclosures comprise depositing mechanisms, and more particularly a device in the shape of a dome bearing the substrates and more one or several sources for emitting substances. I

Now, an enclosure provided with depositing mechanisms is very difficult to clean perfectly. Despite all precautions taken, some dust forcibly remains within that enclosure. At the time of previous emptying of the enclosure, after the fixing of the substrates on the dome, dust is drawn in a swirl and is deposited partly on the substrates.

To avoid that disadvantage, the enclosure for depositing thin layers in a vacuum according to the invention, which comprises at least one source for emitting a substance, arranged facing the concave face of a dome, is characterized inthat the said dome bears at least one substrate protection device, each of these devices comprising:

A trough bearing substrate, fast with the concave face of the said dome;

A cranked lever suspended in the vicinity of its elbow by an axe at the periphery of the said dome and consisting of a first arm supporting a cover and a second arm;

A control mechanism fixed to the convex face of the said dome transmitting a rotating movement to the second arm about the said axe, so that the cover supported by the first arm shades or exposes the substrates contained in the said trough.

During the previous emptying of the enclosure, all the covers are closed so as to protect the substrates from dust. A first advantage of the invention is therefore that it obtains substrates whose cleanliness is not altered by dust.

The present invention also enables the depositing of a particular substance on the substrates contained a single trough to be proceeded with, without depositing on the substrates contained in the other troughs.

The present invention moreover has the advantage of preventing irregular depositing of a substance charged with impurities at the outset of the depositing operation, when that substance is spread unequally within the enclosure. For that purpose, all that is needed is to keep the covers closed.

The present invention has moreover the advantage of enabling the depositing of a substance on the substrates to be stopped suddenly by turning down the covers as required to shade the said substrates.

According to one particularlity of the invention, the troughs and the corresponding covers may be detached from their support, this enabling the substrates to be conveyed out of the enclosure without contaminating them by contact. A trough and the corresponding cover are, to great advantage, of the type such as described in my copending U.S. application Ser. No. 317,305, filed on Dec. 21, 1972, in the applicants name.

To simplify the description, the following text will examine only depositing by evaporation in a vacuum, but

it must be well understood that the invention may quite as well apply to other methods for depositing in a vacuum, and more particularly to spraying.

The following description with reference to the accompanying drawings will make it easier to understand how the invention may be implemented.

FIG. 1 shows a protection device mounted on the dome of the enclosure according to the invention.

FIG. 2 shows an evaporation vacuum enclosure according to the invention.

Such as it is shown in FIG. 1, the protection device 1 comprises a trough 2 mounted on the concave face of a dome 3, a cranked lever 4 suspended in the vicinity of its elbow by an axle 5 at the periphery of the dome 3 and a control mechanism 6 fast with the convex face of the dome 3.

The trough 2 comprises a groove 7, formed in its periphery, in which is inserted an O-ring 8. That trough is provided with fixing means enabling one or several substrates 9 to be maintained therein.

The cranked lever 4 consists of a first arm 10 at whose end is fixed a cover 11, and a second arm 12 connected to the control mechanism 6.

This mechanism 6 comprises two bellows l3 and 14 placed on either side of a moving piston 15 and each comprising a fixed end l6, 17 fast with the dome 3, and a mobile end 18, 19 fast with the piston 15 whose rod 20 is connected to the end of the second arm 12.

Each of the bellows l3 and 14 is supplied by a compressed air inlet duct 21 and 22. When the cover 11 is open (as shown in the figure), and it is required to be closed, fluid is sent under pressure into the bellows l3, and the piston 15 moves towards the right, making the second arm 12 rotate to the right about the axle 5, and bringing the first arm 10 into a position close to the horizontal. The cover 11 is applied to the O-ring 8 of the trough 2, thus protecting the substrates 9 from contamination by the outside medium.

When the cover 11 is required to be opened, fluid is sent under pressure into the bellows 14, the piston 15 moves towards the left, making the second arm 12 rotate to the left about the axle 5, and bringing the first arm 10 into a position close to the vertical. The cover 11 comes into the vertical position, exposing the substrates 9 contained in the trough 2.

The trough 2 is provided with a hole 23 which may be blocked up, enabling a vacuum to be created in that trough covered by the cover 11.

FIG. 2 shows a vacuum enclosure 30 according to the invention, in which only the elements necessary for understanding this invention have been shown.

That enclosure 30 comprises a dome 3 provided with several protection devices 1, l the device 1 being shown open and the device 1 being shown closed.

That dome 3 is mobile about its vertical axis by means of a motor 31, through a gear train 32. At the center of the dome 3, a measuring device having a piezoelectric quartz 33 is installed, showing the thicknesses of the deposit.

Several crucibles such as 35, 35 each containing a substance which, when they are heated, evaporate that substance within the enclosure, are arranged on the base 34 of the enclosure 30.

To effect deposits on the substrates, the assembling, outside the enclosure, of the substrates in the troughs 2, 2' is proceeded with, the covers 11, 11 are closed, and a vacuum is created in the troughs, so that each cover is applied hard against the seal of the corresponding trough.

The troughs 2, 2' are assembled on the dome 3 of the enclosure 30 and the covers 11, 11' at the end of the first arms 10, of the levers 4, 4', then a vacuum is created in that enclosure. During that operation, the substrates are protected from dust.

Once the vacuum has been created, a certain crucible 35 is heated, and the required trough 2 is brought above the said crucible. When the period known as the pre-heating period is ended, the cover 11 of the trough 2 may be opened.

When the measuring device 33 indicates that the required thickness of the deposit is reached, the cover 11 is closed, and although the vapor is still in suspension in the enclosure, it can no longer be deposited on the substrates. By making the dome turn, the required troughs may be brought successively above the crucible 35 and the same cover opening and closing operations may be begun again.

To proceed with the depositing of a second metal, it is sufficient to stop the heating of the first crucible 35 and to heat the second crucible 35' and to begin the preceding operations again. Once all the deposits are ended, the pressure within the enclosure is restored, and the troughs are removed to collect the substrates easily outside the enclosure.

It may therefore be seen that it is possible to deposit thin layers in the required order on the substrates contained in the various troughs and that this order is arbitrary for each trough.

It is seen, on the other hand, that the beginning of depositing (opening of a cover) and the stopping (closing of that cover) may be fixed accurately.

The rise of the vacuum enclosure according to the invention, provided with the protection devices, is a particular advantage for producing substrates which are not contaminated by dust, as well as regular thin layers having a well-defined thickness.

Although the vacuum enclosure which has just been described appears to afford the greatest advantages for implementing the invention, it will be understood that various modifications may be made thereto without going beyond the scope of the invention, it being possible to replace some of its elements by other elements capable of fulfilling the same technical function or an equivalent technical function therein, more particularly for adapting that enclosure to depositing methods other than evaporation, such as spraying. Naturally, devices for controlling levers, which are equivalent to the devices described and implementing, more particularly, electrical, magnetic or electromagnetic means may also be provided.

What is claimed is:

1. ln an apparatus for depositing thin layers of a substance on a substrate in a vacuum including a vacuum enclosure and at least one source in said enclosure for emitting a substance, the improvement comprising a dome supported in said enclosure facing said source, at least one substrate protection device secured to said dome including a disk-shaped receptacle carrying at least one substrate facing said source, a cranked lever pivotally mounted by an axle at the periphery of said dome, a cover for sealing said receptacle supported on one arm of said cranked lever, and operating means supported on said dome and connected to the other arm of said cranked lever for rotating said cranked lever to thereby translate said cover to and away from said receptacle for effecting sealing closure thereof.

2. An apparatus as defined in claim 1 wherein said operating means includes first and second bellows disposed on respective sides of a control piston connected by way of a piston rod to said other arm of said cranked lever, one end of each of said first and second bellows being secured to said dome and the other end thereof being secured to said piston, and means for supplying fluid under pressure selectively to said bellows.

3. An apparatus as defined in claim 2 wherein said receptacles and said covers are removably supported on said dome and said cranked lever, respectively.

4. An apparatus as defined in claim 1 wherein a plurality of receptacles carrying substrates are supported on said dome facing said source.

5. An apparatus as defined in claim 4 wherein a plurality of sources of substance to be deposited are provided in said enclosure and said dome is mounted for rotation to selectively position said receptacles with respect to said sources.

6. An apparatus as defined in claim 5 wherein each receptacle has a cranked lever, a cover and operating means associated individually therewith.

7. An apparatus as defined in claim 6 wherein said operating means includes first and second bellows disposed on respective sides of a control piston connected by way ofa piston rod to said other arm of said cranked lever, one end of each of said first and second bellows being secured to said dome and the other end thereof being secured to said piston, and means for supplying fluid under pressure selectively to said bellows.

8. An apparatus as defined in claim 7 wherein said receptacles and said covers are removably supported on said dome and said cranked lever, respectively.

9. An apparatus as defined in claim 1 wherein said substrate protection device, comprises a disk-shaped receptacle having a rim with an annular channel disposed in the periphery thereof, an O-ring disposed in said channel so as to protrude therefrom, a hole formed in the body of the receptacle having a fluid conveying duct connected thereto capable of connection to a source of vacuum, valve means for selectively closing said duct, means for supporting at least one substrate in said receptacle, said cover being capable of closing said receptacle by contact with said O-ring. 

1. In an apparatus for depositing thin layers of a substance on a substrate in a vacuum including a vacuum enclosure and at least one source in said enclosure for emitting a substance, the improvement comprising a dome supported in said enclosure facing said source, at least one substrate protection device secured to said dome including a disk-shaped receptacle carrying at least one substrate facing said source, a cranked lever pivotally mounted by an axle at the periphery of said dome, a cover for sealing said receptacle supported on one arm of said cranked lever, and operating means supported on said dome and connected to the other arm of said cranked lever for rotating said cranked lever to thereby translate said cover to and away from said receptacle for effecting sealing closure thereof.
 2. An apparatus as defined in claim 1 wherein said operating means includes first and second bellows disposed on respective sides of a control piston connected by way of a piston rod to said other arm of said cranked lever, one end of each of said first and second bellows being secured to said dome and the other end thereof being secured to said piston, and means for supplying fluid under pressure selectively to said bellows.
 3. An apparatus as defined in claim 2 wherein said receptacles and said covers are removably supported on said dome and said cranked lever, respectively.
 4. An apparatus as defined in claim 1 wherein a plurality of receptacles carrying substrates are supported on said dome facing said source.
 5. An apparatus as defined in claim 4 wherein a plurality of sources of substance to be deposited are provided in said enclosure and said dome is mounted for rotation to selectively position said receptacles with respect to said sources.
 6. An apparatus as defined in claim 5 wherein each receptacle has a cranked lever, a cover and operating means associated individually therewith.
 7. An apparatus as defined in claim 6 wherein said operating means includes first and second bellOws disposed on respective sides of a control piston connected by way of a piston rod to said other arm of said cranked lever, one end of each of said first and second bellows being secured to said dome and the other end thereof being secured to said piston, and means for supplying fluid under pressure selectively to said bellows.
 8. An apparatus as defined in claim 7 wherein said receptacles and said covers are removably supported on said dome and said cranked lever, respectively.
 9. An apparatus as defined in claim 1 wherein said substrate protection device, comprises a disk-shaped receptacle having a rim with an annular channel disposed in the periphery thereof, an O-ring disposed in said channel so as to protrude therefrom, a hole formed in the body of the receptacle having a fluid conveying duct connected thereto capable of connection to a source of vacuum, valve means for selectively closing said duct, means for supporting at least one substrate in said receptacle, said cover being capable of closing said receptacle by contact with said O-ring. 